Whelen screw size

[josh_thomas19]

I have a whelen beta with beta1 control head installed in my truck. Purchased siren used and the two set screw heads on the rotary knob are almost completely stripped. I can still turn but it sometimes twists the knob w/o the stem its on. Called whelen distributor and they said they would sell me a new knob with screws for the low price of $26 dollars plus $8 shipping. thought that was a little steep. If I could replace the screws then it would be perfect. I can't find the size though anywhere. If anyone knows the size or where I could find either the screws or screws and knob that would be awesome. Thank you for your time and have a nice day!

 

[C2Installs]

They are generally called control knobs. Radio Shack carries knobs similar to what you need, IIRC. I am assuming that the shaft that the knob mounts on has a flat spot milled into it, so it king of looks like a D from the top? Typical shaft diameter is 3/16" or 1/4". Take the old one with you and see. The key, besides shaft diameter and attachment method, is where the index mark is in relation to the shaft flat. Typically is is opposite, but you need to be sure for the functions to be accurate. Good luck.


Here are a few quick links...


This is very similar to the Beta Knob: Control panel knob 232 black matte d-shaft knobs 25 pc.


And this is from Radio Shack's Website: Knobs - Component parts - RadioShack.com


Google search: control knobs - Google Search


Some cool stuff here: Control Knobs - EHCKnobs.com


More: Knobs


OEM supplier: Plastic Knobs, Metal Knobs, Clamping Knobs, Control Knobs, Appliance Knobs